| Healthy | Emphysema | IPF |
---|---|---|---|
Baseline \( \overset{.}{V} \) O2 | 0.62 ± 0.9 | 0.60 ± 0.12 | 0.75 ± 0.18 |
\( \overset{.}{V} \) O2 Amp (l · min−1) | 1.48 ± 0.54 | 0.40 ± 0.11a | 0.41 ± 0.14a |
\( \overset{.}{V} \) O2 TD (s) | 15 ± 5 | 11 ± 7 | 11 ± 7 |
\( \overset{.}{V} \) O2 τ (s) | 31 ± 7 | 65 ± 11a | 69 ± 7a |
\( \overset{.}{V} \) O2 MRT (s) | 52 ± 12 | 81 ± 18a | 92 ± 19a |
\( \overset{.}{V} \) O2 SC Amp (l · min−1) | 0.19 ± 0.10 | 0.01 ± 0.01a | 0.01 ± 0.01a |
\( \overset{.}{V} \) O2 SC Amp (% EE \( \overset{.}{V} \) O2) | 7 ± 3 | 1 ± 1a | 1 ± 1a |
HR Amp (beats · min−1) | 58 ± 11 | 22 ± 10a | 21 ± 10a |
HR τ (s) | 36 ± 12 | 119 ± 20a | 87 ± 19ab |
[HHb] TD (s) | NA | 18 ± 9 | 15 ± 2 |
[HHb] τ (s) | NA | 51 ± 23 | 35 ± 29 |
[HHb] τ’ (s) | NA | 69 ± 15 | 54 ± 35 |
[HHb]: \( \overset{.}{V} \) O2 ratio | NA | 1.07 ± 0.14 | 1.21 ± 0.07 |
Work rate (W) | 155 ± 56 | 37 ± 12 | 64 ± 9 |